Audi FSI Technology: From Le Mans Victory To The Latest RS 5

In this second installment of Audi’s Moments of Truth video series, which gives us a behind-the-scenes look at the automaker’s epic achievements in motorsport, we learn the story of how FSI technology led to the Audi Joest R8 victory at the 24 Hours of Le Mans back in 2001.

The video features one of the winning drivers, Tom Kristensen, as well as Audi race engineer Jo Hausner. Together, they explain how FSI technology gave them significant fuel efficiencies and performance advantages that ultimately helped them overcome the grueling elements and torrential rain of the 2001 race.

An acronym for Fuel Stratified Injection, FSI technology is essentially a fuel injection system where fuel is injected directly into the cylinder, in very precise amounts. In this way the optimal amount of fuel is burned throughout the rev range, allowing for ultra lean mixtures of fuel and air during low load situations and slightly richer mixtures when maximum power is demanded.

Today, you’ll find FSI technology in most Audi models, with the latest to adopt the technology being the 2013 RS 5. The car’s 4.2-liter V-8 engine is rated at 450 horsepower and 317 pound-feet of torque, helping it accelerate from 0-60 mph in just 4.5 seconds and easily reaching an electronically limited top speed of 174 mph. As revealed by one of the RS 5's engineers in this video, FSI helps the mighty V-8 freely rev to 8,500 rpm and beyond while also delivering excellent throttle response.

Stay tuned for the third and final installment of the series later today. In the meantime, check out the first installment, which centers on the development of the five-cylinder engine at Audi and its use in the legendary Audi 90 Quattro.